Lubricant for rolling metals



U.S. Cl. 25249.5 10 Claims ABSTRACT OF THE DISCLOSURE Soluble oilcompositions comprising lubricating oil containing a fatty acid, amorpholine, and an alkylene polyol are useful in hot rolling of metals.

Background of the invention The subject matter of the invention pertainsto lubricants containing an organic acid and a nitrogen-containing base.More particularly, it pertains to lubricants which may be eitherwater-in-oil or oil-in-Water emulsions.

It is known from the prior art that satisfactory lubricants for use inhot rolling non-ferrous metals such as aluminum are obtained by admixingcertain soluble oils with water to form emulsions. US. Patent No.3,311,557 describes such a soluble oil which comprises a minerallubricating oil containing an additive combination comprising analkanolamine, sufiicient fatty acid to provide free fatty acid and analkylene polyol. The soluble oil when admixed with water forms afinished lubricant for lubricant for use in hot rolling of, for example,aluminum. The lubricant provides good cooling and lubricatingproperties, bright surface finish, and resistance to staining and metalpickup.

Although the lubricants described in the above-mentioned patent aresatisfactory in hot rolling non-ferrous metals, improvements withrespect to lubricant emulsion stability, oil aging characteristics, andthe method of preparing the oil, Would be highly desirable.

Summary It has now been described that the above-mentioned improvementsin the lubricants described in US. Patent No. 3,311,557 can be achievedwithout adversely affecting the other properties and qualities of theoil by replacing the alkanolamine of the soluble oil with morpholine.

Description of the preferred embodiments Any mineral oil may be used asthe base for the soluble oil. Preferably, the oil used is a HVIlubricating oil, i.e. one having the viscosity index (Dean-Davis of atleast 80, preferably 90100. Mineral oil fractions of this type arederived from parafiinic, naphthenic or mixed base crudes. Viscosity asdetermined at 100 F. is in the range from about 75 to 250 SUS,preferably between 100 and 150. A typical mineral base of this kind is ahigh viscosity index refined mineral lubricating oil having thefollowing properties:

GR, API 60 C 32.2 Color, ASTM 1 Pour point, F. 5 Flash, F. COC 370 Fire,F. 435 Viscoosity, SUS at 100 F. 103 Viscosity index 93 Neutralizationnumber 0.01

The low and medium viscosity index oils (80 VI), however, may also beused as the mineral oil base for the soluble oils of the presentinvention.

The fatty acid used in the present composition includes fatty acids offrom 12 to 30, preferably 14 to 18 carbon nited States Patent 9 F3,444,080 Patented May 13, 1969 atoms and may be derived from animal,vegetable or mineral sources, such as fatty acid obtained from cottonseed oil, soy bean oil, coconut oil, corn oil, palm oil, lard oil,tallow and pure saturated and unsaturated fatty acids, such as stearic,oleic or linoleic acids. Oleic acid or mixed fatty acids having a highproportion of oleic acid are particularly suitable because of lowmelting point. A suitable fatty acid is sold by Emery Industries underthe trade name of Emery 3305, the major constituents and approximateamount being oleic acid (45% wt.), stearic acid (15% wt.), linoleic acid(15% Wt.), and palmetic acid (15% M) A particularly suitable fatty acidis Emery 3252 which is of low melting point and results in an oil blendof low pour point. The amount of fatty acid used in the soluble oil isfrom about 10% to about 35% by weight and preferably from about 15% to30% by weight.

Only sufficient morpholine is used to form the salt of a portion of thefatty acid so as to leave a relatively large amount of free fatty acidin the soluble oil, e.g. sufficient morpholine is used to combine withon the order of from about 1540% of the fatty acid. The amount ofmorpholine is controlled so that the ratio of the total baseneutralization number-electrometric (TBN-E as determined by the ASTM 664method) to the total acid neutralization number-electrometric (TAN-E asdetermined by the ASTM 664 method) of the soluble oil is in the rangefrom about 0.15 to 0.4 and preferably from 0.15 to 0.3. In terms ofpercent by Weight of the composition this amount is from about 1.5% toabout 2.0% of morpholine based upon the above quoted percentages ofacid. The amount of morpholine is considered to be critical, since whenthis ratio is too low, emulsions of the soluble oil with water may havepoor stability. At high ratios, pick-up of aluminum fines by theemulsions may become excessive.

Surprisingly, if cyclic amines other than morpholine are used to preparethe oils of the present invention, the resulting oils do not formsatisfactory emulsions, e.g. oils containing aniline, pyridine, benzylamine, p-aminophenol, p-phenylenediamine, p-anisidine, 3-aminopyridine,o-phenetidine, 2-pyridol, cyclohexyl amine, piperazine, ordicyclohexylamine show no ability to form emulsions; oils containingpiperidine and 2,6-dimethylmorphine yield emulsions, but of poorquality; and oils containing N- methylmorpholine yield emulsions whichare inferior to morpholine-containing oils, but better than oilscontaining any of the other cyclic amines.

Alkylene polyols suitable for use in the composition of the inventionare those wherein the alkylene group has from 4-8 carbon atoms.Particularly suitable and preferred alkylene polyols are the diols, suchas hexylene glycol, 1,2-hexane diol, 1,5-pentane diol, 1,5-hexane dioland the like. From about 2 to 15% by weight and preferably from 8 to 12%by weight of the alkylene polyol is used in the soluble oil.

Other additives can be added to compositions of this invention in orderto improve their performance. For example, emulsions containing fattyacids are susceptible to deterioration, especially when used at elevatedtemperatures for long periods of time. Such emulsions develop anextremely strong, foul and undesirable odor which renders themobjectionable. It is generally desirable to add a small amount of agermicidal agent to inhibit bacterial growth and fermentation. Formalin(aqueous solution of approximately 40% formaldehyde) and phenoliccompounds, e.g. phenol, chlorophenols such as tetrachlorophenol, phenylphenols such as o-phenyl phenol, and the like are Well known germicidalagents. The phenolic germicidal agents are preferred and are availablecommercially. The amount of germicidal agent used generally does notexceed 5% by weight, usually from 0.1-

1% by weight added to the soluble oil is very effective. Minor amounts,e.g., 0.l1% by weight of antioxidants can be used. A highly suitableantioxidant is 2.,6-ditertiary butyl-4-rnethyl phenol.

Illustrative examples of soluble oils of this invention comprise:

Composition A: Percent weight Emery 3305 fatty acid 23.0 Morpholine 2.0Hexylene glycol 10.0 HVI neutral (VI 94, 105 SUS at 100 F.) 65.0

100.0 Composition B:

Oleic acid 20.0 Morpholine 1.6 Hexylene glycol 11.0 Minerallubricatingoil (same as A) 67.4

100.0 Composition C:

Oleic acid 17.0 Morpholine 1 .5 Hexylene glycol 8.0 Mineral lubricatingoil (same as A) 73.0 Germicidal agent (0.25% Wt. Dowicide C.O.

+0.25% wt. Dowicide 6) 0.5

100.0 Composition D:

Emery 3305 fatty acid 23.1 Morpholine 1.7 1,5-Pentane diol 10.0 Minerallubricating oil (same as A) 65.2

100.0 Composition E:

Emery 3252 fatty acid 23.2 Morpholine 1.8 Hexylene glycol 10.1 Minerallubricating oil (same as A) 64.4 2,6-ditertiary butyl-4-methyl phenolplus 50 p.p.m. by weight Dow Corning Antifoam A 0.5

100.0 Composition F:

Emery 3305 fatty acid 12.0 Morpholine 1.7 Hexylene glycol 4.0 Minerallubricating oil (same as A) 82.3

100.0 Composition G:

Emery 3305 fatty acid 25.0 Morpholine 2.9 Hexylene glycol 12.0 Minerallubricating oil (same as A) 60.1

100.0 Composition H:

Emery 3305 fatty acid 20.0 Morpholine 1.4 Hexylene glycol 8.0 Minerallubricating oil (same as A) 70.6

100.0 Composition I:

Fatty acid 23.0 Morpholine 1.85 Hexylene glycol 10.0

Mineral lubricating oil (major amount).

In preparing the soluble oil of the present invention the components aremerely blended together using conventional mixing means, such asmechanical agitation. Heating may be used, if desired, to facilitateblending, e.g. temperatures of from F. to 120 F. The preparation of theinstant morpholine-containing soluble oils is relatively simple whencompared to the involved cooking steps required in preparing thealkanolamine-containing soluble oils of the prior art.

Finished emulsions are prepared by admixing, on a volume basis, fromabout 2% to about 10%, preferably about 3% to 6% soluble oil with water.In general, the present soluble oils can be used in concentrations lowerthan those used with conventional soluble oils which is advantageousfrom a cost standpoint. The emulsions form quite readily, which is animportant factor since the mixing of the oil and water is done in thefield by means such as air agitation, propeller mixing and the like. Thecomposition of the emulsion yields a proper balance among the forces ofattraction operating between the oil and water phase, the oil phase andthe metal, and the water phase and the metal. The composition of theemulsion is such that an oil-in-Water emulsion and a water-inoilemulsion are almost equally likely to form spontaneously, yet theresulting emulsion is quite stable.

Typical properties of the compositions of the invention are given inTable 1.

TABLE 1 Property: Value Gravity, API at 60 F. 29.5 Color, ASTM 2.0 Pourpoint, F. 0 Cloud point, F. 28 Flash, F. 300 Viscosity, SSU at F. 113SSU at 210 F. 40.6 W (ASTM D-567) l. 100 Initial pH 7.5 TBN-E, mg.KOH/g. of oil 12 TAN-E, mg. KOH/g. of oil 44 Ratio TBN-E/TAN-E 0.27Saponification No. 45

Sulfated ash, percent w. 0.002

To illustrate other properties and qualities of the compositions of thepresent invention, a comparison is made with a soluble oil (CompositionX) comprising:

Percent wt. Emery 3252 fatty acid 25.0 Hexylene glycol 7.5Diethanolamine 1.5 Mineral lubricating oil (same as A) 66.0

Plus 0.5% W. 2,6-di-t-butyl-4-methyl phenol and 50 p.p.m. Dow CorningAntifoam A.

Since in many instances the soluble oil will be stored prior topreparing the emulsion or finished lubricant, the tendency of the oil todeteriorate when stored is important. To measure this tendency theemulsion stability of emulsions prepared from Compositions E and X wasdetermined using new oil, oil aged at F. for 14 days (equivalent to 2months at 77 F.) and 110 F. for 28 days (equivalent to 4 months at 77F.). The emulsion stability is indicated by preparing an emulsion of oil(6% v.) and distilled water, allowing the emulsion to stand 8 hours, andthen measuring separation of oil and water from a 100 cc. sample. Theresults of this test are given in Table 2 below.

TABLE 2.-STORAGE EFFECT ON EMULSION STABILITY The data of Table 2demonstrates that the compositions of the present invention have lesstendency to deteriorate during storage than similar compositionscontaining an alkanolamine rather than morpholine.

Aging of the emulsion itself is indicated by a test which consists ofpreparing an emulsion having 3% v. oil and 97% v. distilled water,stirring the resulting emulsion at 180 F. for 14 days with make-up waterbeing added as needed to simulate service conditions, and measuringseparation of oil and water from a 100 cc. sample as before. Also thealuminum fines suspension test was carried out to measure the afiinityof the oil for metal. The test consists of mixing 0.1% W. aluminum fines(95% through 200 mesh, 80 to 90% through 325 mesh) with 500 cc. of anemulsion composed of 6% v. oil and 94% v. distilled water. The mixtureis shaken for 2 minutes and allowed to stand for 10 minutes in a 500 cc.graduated cylinder. A pipette is used to withdraw a 50 cc. sample fromthe middle of the mixture which is contained in the 500 cc. cylinder.The remaining steps consist of filtering the sample through an asbestospad in a Gooch crucible, weighing the amount of aluminum recovered fromthe sample, and recording the percent of fines which remains dispersed.A small percentage is desirable. The pH of the emulsion is also given inTable 3. The results of these tests are given in Table 3.

1 Trace oil. 0.5% cream. 2 Trace oil, 1% cream. a Trace oil, 1.5% cream.

The data of Table 3 show that the composition of the present inventionwhich contains morpholine rather than a dialkanolamine is more stablethan Composition X and gives satisfactory results with respect to metalpickup. The constant pH of 8.0 shows that the emulsion has goodresistance to air oxidation.

I claim as my invention:

1. A soluble oil suitable for use in hot rolling nonferrous metals whichcomprises a major amount of a mineral oil, from about 10% to about 35%by weight of a fatty acid having from 12 to 30 carbon atoms, from about2% to about 15% by weight of an alkylene polyol wherein the alkylenegroup has from 4 to 8 carbon atoms, and from about 1.5 to about 2.0% byweight of morpholine.

2. The soluble oil of claim 1 wherein the amount of fatty acid is from15 to 30% by weight and the amount of alkylene polyol is from 8 to 12%by weight.

3. The soluble oil of claim 2 wherein the alkylene polyol is hexyleneglycol.

4. The soluble oil of claim 3 wherein the fatty acid comprises oleicacid.

5. The composition of claim 4 wherein the composition comprises about23% fatty acid, 10% hexylene glycol, and 1.85% morpholine.

6. The composition of claim 5 containing from about 0.1% to 1% by weightof 2,6-ditertiary butyl-4methyl phenol.

7. The composition of claim 5 wherein the mineral oil has a viscosity atF. of from 100 to SSU.

8. An aluminum hot rolling composition comprising a major amount ofwater and from about 2 to about 10% by volume of the soluble oil ofclaim 1.

9. An aluminum hot rolling composition comprising a major amount ofwater and from about 2 to about 10% by volume of the soluble oil ofclaim 5.

10. An aluminum hot rolling composition comprising a major amount ofwater and from about 2 to about 10% by volume of the soluble oil ofclaim 6.

References Cited UNITED STATES PATENTS 2,815,560 12/1957 Buxton 25252 XR3,071,544 1/1963 Rue 25249.5 XR 3,268,447 8/1966 Dickey et a1. 252515 XR3,311,557 3/1967 Schiermeier et a1. 25252 XR DANIEL E. WYMAN, PrimaryExaminer.

W. I. SHINE, Assistant Examiner.

US. Cl. X.R.

